effect of drought stress on morphological and physiological characteristics of wheatgrass and tall fescue

in this study, the effect of drought stress on morphological and physiological characteristics of wheatgrass and tall fescue was investigated in a factorial-split plot in time arrangement based on a completely randomized design with three replications. after turf establishment, half pots were exposed to drought stress and the half other were completely irrigated. based on the results tall fescue had higher color and lower percent leaf firing during first 10 days of drought stress, but after this period, the percent leaf firing in tall fescue increased, so that it had higher percent leaf firing and lower color than wheatgrass in the end of experiment. the results showed that under drought stress conditions was not observed the significant difference between two species in leaf relative water content. in wheatgrass, proline content of stressed plants was equal to control plants during first 10 days of drought stress but with prolonged stress treatment, the proline content increased significantly. despite wheatgrass which had moderate rate for closed stomata percentage during stress period, tall fescue showed a great increased in this index and reached to 89.52% at the end of 20th day. also in drought stress, the stomata density increased and stomata diameter decreased significantly. therefore, based on the results in long drought stress, wheatgrass had higher drought resistance than tall fescue.